To assess the immunogenicity, safety, and tolerability of hepatitis A vaccine (VAQTA^TM) in healthy children and adolescents.

Eligible subjects aged 2 to 17 years received 25 U/0.5 mL of VAQTA^TM intramuscularly at 0 and 24 week schedule. Bleeds were obtained prior to vaccination and 4 weeks after the second dose to ascertain serostatus. To detect antibody to HAV after vaccination with an inactivated HA vaccine, a modification of the Abbott® HAVAB kit was used. Sample with titers > 10 mIU/mL were considered seroconverted. Adverse experiences were monitored.

102 subjects(54 male, 48 female) were enrolled. The mean age was 6.8±3.5 years. Two subjects were seropositive, two were lost of follow up. 88 subjects were available for a per protocol analysis and 90 for all subjects with serology after the second dose, and ten withdral. All subjects(95% CI, 94.8〜 100) seroconverted. Geometric mean titers was 7,991.1(95% CI, 6,481.1〜9,852.7) with very little difference in per protocol analysis and all subjects analysis. Adverse experiences to VAQTA^TM were generally mild and transient.

The pediatric two-dose regimen of VAQTA^TM was found to be highly im- munogenic, generally well tolerated and resulted in 100% seroconversion. Regarding Korea is in transition from a high to low risk region resulting in a paradox increase of clinical disease and disease burden, routine vaccination should be considered in order to control hepatitis A effectively.